1. Field of the Invention
The present invention relates to a method of hair depilation; in particular, the present invention relates to a method of hair depilation using an Nd:YAG laser which causes local heating at the hair bulb due to the absorption of the oxyhemoglobin contained in the capillaries. The treatment can be performed on a single hair or a group of hairs using the Nd:YAG laser.
2. Description of the Related Art
At present, various methods for hair depilation using coherent light sources, such as lasers, are available. In particular, U.S. Pat. No. 5,059,192 describes a method of depilation based on the absorption of heat by melanin present in the hair follicle. The heat is provided by a Q-switched ruby laser, operating at a wavelength of 694 nm. The subsequent heating is provided at a direction substantially vertical to the hair follicle opening. Due to the heat, the follicle is severely damaged, interrupting the normal vital cycle and therefore its re-growth.
U.S. Pat. No. 5,423,803 uses a contaminant applied to the skin of a patient as a means for absorption of laser impulses of high peak intensity and very short duration. This causes irreversible damage to the hair bulb. For this purpose, a Q-switched Nd:YAG laser with emission at 1.06 .mu.m is used, exploiting the minimum absorption that both the skin and the melanin have at this wavelength. U.S. Pat. No. 4,388,924 discloses a method that focuses a beam of light to destroy the vascularized part of the follicle. The beam of light is directed at an angle with respect to the hair follicle opening such that the beam of light is directed at the hair root. The hair root is heated, thereby causing damage to the blood vessels in the hair root. This in turn causes damage to the hair, preventing its re-growth.